Mattison, 59, was hired as Baltimore's linebackers coach last February. Although he has only one year of NFL experience, Mattison was a defensive coordinator at the college level at Michigan, Notre Dame and Florida.
"Greg is a guy that I have full trust and belief in, and not just because of his track record," Ravens head coach John Harbaugh said. "He's been successful at every stop, but the job he did this year with our guys, I think he established himself as a premier coach in the NFL. If you talk to our players, they'll tell you the same thing."
Mattison replaces Ryan, who served as Baltimore's defensive coordinator for four seasons before leaving last week to become head coach of the New York Jets.
"Rex did a tremendous job of getting the most out of his players, having them believe and trust what they're doing and to be accountable for what they're doing," Harbaugh said. "Those are the strengths that I've always felt Greg had as a coach."
Harbaugh briefly considered going outside the organization to find a replacement for Ryan, but it didn't take long for him to realize the best move was to choose between four men who worked under Ryan this season: Mattison, Vic Fangio, Chuck Pagano and Clarence Brooks.
Fangio was promoted to linebackers coach, and special teams coordinator Jerry Rosburg was given the additional title of assistant head coach.
Mattison said he intends on employing the same kind of pressure-packed defense that Ryan deployed with uncanny success.
"I believe strongly that you have to be aggressive, that you have to be an attacking defense," Mattison said. "Obviously, that's been the M.O. of the defense here for years. In looking at what we do defensively, we don't plan on changing a great deal. It's not broken by any means."
Mattison started his coaching career at the high school level in 1971 before serving as an assistant at Illinois, Cornell and Northwestern. He met Harbaugh while serving a six-year stint at Western Michigan from 1981 to 1986. Mattison then spent two years at Navy, followed by stays at Texas A&M, Michigan, Notre Dame and Florida.
Copyright 2009 by The Associated Press